Eye monitoring system and method

Abstract

A system for use with a head-mountable display device, HMD, operable to present content to a user, the system comprising a temperature sensor unit configured to detect a temperature associated with at least one of the user's eyes and/or an ambient temperature associated with the HMD, a blink sensor unit configured to detect blinking of one or both of the user's eyes, a threshold determination unit configured to determine a threshold value for a blink rate of the user in dependence upon the one or more detected temperatures, and a processing unit configured to determine a blink rate of the user in dependence upon the detected blinks, and to modify the content presented by the HMD in response to the blink rate of the user falling below the threshold value.

1 . A system for use with a head-mountable display device, HMD, operable to present content to a user, the system comprising:
 a temperature sensor unit configured to detect a temperature associated with at least one of the user's eyes and/or an ambient temperature associated with the HMD;   a blink sensor unit configured to detect blinking of one or both of the user's eyes;   a threshold determination unit configured to determine a threshold value for a blink rate of the user in dependence upon the one or more detected temperatures; and   a processing unit configured to determine a blink rate of the user in dependence upon the detected blinks, and to modify the content presented by the HMD in response to the result of a comparison between the blink rate of the user and the threshold value.   
     
     
         2 . The system of  claim 1 , wherein the temperature sensor unit comprises a thermal camera configured to capture images of one or both of the user's eyes. 
     
     
         3 . The system of  claim 1 , wherein the blink sensor unit is formed as a part of a gaze tracking arrangement associated with the HMD. 
     
     
         4 . The system of  claim 1 , wherein the threshold determination unit is configured to update the threshold value in response to a change in detected temperature, a change in detected blink rate, and/or an elapsed time. 
     
     
         5 . The system of  claim 1 , wherein the threshold determination unit is configured to select from a plurality of predefined thresholds, or to calculate a new threshold value. 
     
     
         6 . The system of  claim 1 , wherein the processing unit is configured to determine a rate of change of blink rate of the user, to generate a prediction of when the blink rate of the user will fall below the threshold, and to modify the content in dependence upon this prediction. 
     
     
         7 . The system of  claim 1 , wherein the processing unit is configured to generate a warning to be provided to the user when the blink rate of the user is determined to have fallen below the threshold value. 
     
     
         8 . The system of  claim 1 , wherein the processing unit is configured to modify the content in dependence upon the magnitude of the difference between the blink rate of the user and the threshold value. 
     
     
         9 . The system of  claim 1 , wherein the processing unit is configured to generate a stimulus to induce one or more blinks from the user in dependence upon the blink rate of the user and/or a difference between the blink rate of the user and the threshold value. 
     
     
         10 . The system of  claim 1 ,
 wherein the processing unit is configured to determine a rate of change of one or more of the detected temperatures, and   wherein the threshold determination unit is configured to estimate a future threshold value in dependence upon the determined rate of change of one or more of the detected temperatures.   
     
     
         11 . The system of  claim 1 , wherein the processing unit is configured to modify one or more rendering and/or display parameters associated with the content in dependence upon a difference between the blink rate of the user and the threshold value. 
     
     
         12 . The system of  claim 1 , comprising a content analysis unit configured to determine one or more visual properties of the content, wherein the threshold determination unit is configured to determine the threshold value in dependence upon the determined one or more visual properties of the content. 
     
     
         13 . A method for use with a head-mountable display device, HMD, operable to present content to a user, method comprising:
 detecting a temperature associated with at least one of the user's eyes and/or an ambient temperature associated with the HMD;   detecting blinking of one or both of the user's eyes;   determining a threshold value for a blink rate of the user in dependence upon the one or more detected temperatures;   determining a blink rate of the user in dependence upon the detected blinks; and   modifying the content presented by the HMD in response to the result of a comparison of the blink rate of the user and the threshold value.   
     
     
         14 . A non-transitory machine-readable storage medium which stores computer software which, when executed by a computer, causes the computer to perform a method for use with a head-mountable display device, HMD, operable to present content to a user, method comprising:
 detecting a temperature associated with at least one of the user's eyes and/or an ambient temperature associated with the HMD;   detecting blinking of one or both of the user's eyes;   determining a threshold value for a blink rate of the user in dependence upon the one or more detected temperatures;   determining a blink rate of the user in dependence upon the detected blinks; and   modifying the content presented by the HMD in response to the result of a comparison of the blink rate of the user and the threshold value.